Transgender youth who initiated testosterone therapy didn’t experience increased anger or irritability a year later—in fact, some demonstrated reduced aggression, according to a
study published this week in the
Journal of Adolescent Health.
Why It’s Relevant
Research has shown that gender-affirming hormone therapy is associated with
improved mental health outcomes for transgender youth with gender dysphoria. However, some youth and their families have cited concerns over the potential side effects of using testosterone to induce masculinizing features—such as emotional dysregulation, aggression, and irritability.
By the Numbers
- Researchers identified 178 gender-diverse adolescents and young adults (92% identified as transmasculine/male, 58% White, average age 16) in the United States who initiated testosterone therapy. All the youth had completed puberty and had no exposure to puberty blockers.
- On average, self-reported levels of anger, aggression, irritability, externalizing problems, and oppositional defiant problems were within normal ranges at baseline (standardized scores of <60 on the NIH Toolbox and Youth Self Report questionnaires), and they remained about the same 12 months after initiating testosterone therapy.
- 45.5% of youth reported slightly elevated anger and/or externalizing behaviors at baseline, and their average levels of these behaviors dropped to the normal range at 12 months.
- At the individual level, 69.6% of participants had consistently normal levels of anger between baseline and 12 months, 19.2% moved from elevated to normal anger, and 11.2% moved from normal to elevated.
The Other Side
The study didn’t capture potential changes in anger, irritability, or aggression in the first few months after initiating testosterone therapy. Additionally, the authors cautioned against overinterpreting the statistically significant decreases in some scores given the low levels of symptom severity endorsed across the overall sample. This analysis also did not include any comparison groups.
Takeaway Message
The study suggests that, despite concerns commonly raised by youth and their families, there is not a clinically significant concern for increased anger, irritability, or aggression as a side effect of testosterone. The researchers also noted that transgender adolescent and young adult males are “endorsing levels of anger, irritability, and aggression comparable to normative samples over time as a whole.”
Related Information
Source
T. Zachary Huit, et al. Anger, aggression, and irritability in transgender and gender diverse youth following testosterone initiation: a 12-month longitudinal analysis.
Journal of Adolescent Health. Published February 25, 2026. doi:
10.1016/j.jadohealth.2025.12.257
(Image: Getty Images/iStock/ayo888)